Polycom EF2241 - Manual (Page 45)

T
ROUBLESHOOTING
© Polycom, Inc. 43 V ORTEX EF2241 Reference Manual
If you suspect the loudspeaker is introducing nonlinearities into the room acoustic
path, take these steps to minimize its influence on the echo canceller.
• Keep the loudspeaker’s volume level at less than three-eighths of full scale. If
higher volume is required, the EF2241 should operate effectively at volume set-
tings of up to 50 percent of full scale. At more than 50 percent, most audio sys-
tems and loudspeakers introduce significant nonlinearities. The EF2241 may not
adapt under these conditions, and echoes may be heard.
• If the loudspeaker has a bass control, lower it. Excessive bass can cause a boomy
effect that is nonlinear. In addition, excessive bass may cause substantial
mechanical coupling to the microphone through vibrations induced in the hous-
ings and support structures.
• Increase the separation distance between microphones and the loudspeaker. The
EF2241 handles up to 10 dB of room gain between the loudspeaker and the
microphone. You may be exceeding this limit if the loudspeaker is pointed
directly at the microphones or if the loudspeaker volume is excessive (loud-
speaker placement is not critical, but it should not be pointed directly at the
microphones).
C
ONTACTING
T
ECHNICAL
S
UPPORT
If these troubleshooting guidelines don’t resolve the problem you are experiencing
with the EF2241, please check our web site (http://www.polycom.com) for the most
current technical support information (go to Products & Services, then to Voice Prod-
ucts, then to Installed Voice Systems). If you have further questions, please contact us
at:
Applications Engineering
Polycom Installed Voice Business Group
1720 Peachtree Street NW Suite 220
Atlanta, GA 30309-2439
Phone: (800) 932-2774
Fax: (404) 892-2512
Email: [email protected]
Before contacting us, please review the warranty and repair policy on page 55.